Over 10 years after his death, Karlheinz Stockhausen still occupies a complex and difficult place in the canon of contemporary composers, not only because of the large and multi-faceted body of work he left behind, but also because of his forbidding reputation and the difficulties involved in staging many of his works. Inori, for example, has been performed few times in the version for large orchestra since its première in 1974. This year, it was featured in the finale of the Musikfest Berlin, and was at the climax of the festival’s Stockhausen focus.

Stockhausen conceived Inori as a “creation ceremony”, a ritualistic work for orchestra and two dancers, who perform the solo “melody” of the piece, translated into movements inspired by the prayer gestures of the major world religions. Harmonically, the piece is built around a single repeated tone; the interest in the piece comes rather from finely nuanced developments in dynamics and timbre.

The challenge therefore lies in doing justice to these subtle graduations. Conductor (and composer) Péter Eötvös assisted Stockhausen at the première, and therefore has an ingrained sense for these subtleties. In Berlin, he led the Lucerne Festival Academy, who gave an enthusiastic performance, yet it was only in the work’s closing section that the ensemble really started to create the magic of the piece’s slow timbral evolution. Dancers Diégo Vásquez and Winnie Huang impressed with their seriousness and total commitment to Stockhausen’s vision.

It is in Stockhausen’s works for piano that one can start to appreciate the range of his artistic achievement. Pierre-Laurent Aimard has become an authoritative interpreter of this repertoire, having worked with the composer since he was a young performer in the Ensemble intercontemporain. At the Musikfest Berlin the pianist repeated the astonishing feat of playing the complete solo Klavierstücke, Kontakte for electronics, piano and percussion, and Mantra for two pianos and electronics in less than a week – he first pulled this off for musica viva in Munich in 2015.

The Klavierstücke for solo piano date from the 1950s, and show Stockhausen’s stylistic experiments with Webernian post-serialism in no. III or pointillist polyphony in no. IV. In nos. V – VIII, all written for David Tudor, Aimard brought out the organic and human aspects of the works, giving shape and finding sense in even the most abstruse and complex sections, whilst in no. X he pulled off a masterly act of pure pianism, wearing bandages to protect his hands from the physical demands of rapid fortissimo glissandi.

A few days later, Aimard was joined by his regular duo partner Tamara Stefanovich and sound engineer Marco Stroppa for Mantra. Here, the two pianos (as well as woodblocks and antique cymbals) are electronically transformed with ring modulation, which the pianists adjust themselves during performance. When the electronic elements are combined with Stockhausen’s evident interest in sonic exoticism – the harmony and timbre are reminiscent of Indonesian Gamelan or Japanese Gagaku music – it creates a rich and unearthly sound-world that, nearly 50 years after the piece was composed, is still unique and fascinating. Aimard and Stefanovich gave a masterful performance of this beguiling piece, emphasising the delicate and playful elements of the piece, and coaxing incredible tone colour from the two pianos.